Why go up when you can go down? Basement and lower ground extensions not only add significant living space and value to a property (without sacrificing garden space) but can also be used to create dedicated, private sanctuaries that can be tailored to each owner.

While in some cities skyscrapers still reign supreme, in London, many top-tier townhouses are digging deep for that all important extra living space. From stunning Chelsea townhouses to Notting Hill villas, as well as Mayfair mansions, these stunning homes for sale in London boast beautiful basement gyms, spas, kitchens, and more.

Elystan Place, Chelsea, SW3

Having been totally redeveloped to the highest standard by the award-winning private development and investment company Jubilee Partners, this stunning four-bed, three-bathroom family home benefits from a stand-out basement conversion complete with a versatile gym and studio room, with doors opening into the light-well, alongside a practical bespoke utility room, plant room and a seasonal storeroom.

Other contemporary conveniences behind the attractive restored period façade, include air conditioning throughout, a bespoke kitchen and utility, underfloor heating, Lutron lighting, Water Monopoly bathrooms, integrated Wi-Fi and speakers, and acoustic and thermal insulation. The beautiful garden is also of note, boasting a central outdoor fireplace with gas fire. Accessed by sliding French doors, the effect is a magnificent focal point of the reception room and a great entertaining space all round.

Listed for £5.95m, visit struttandparker.com

Chesterfield Street, Mayfair, W1J

A gorgeous Grade II-listed six-storey townhouse, this luxurious home provides substantial accommodation across its basement, ground and four upper floors, all with lift access. The exemplary property exudes period elegance, with preserved architectural features including high ceilings, intricate cornicing and plasterwork, hand-crafted fireplaces and large sash windows, while at the same time, encompassing contemporary convenience from air-conditioning and underfloor heating to a state-of-the-art security system.

The incredible basement floor benefits from Portland stone underfoot and has been proficiently designed to have a luxurious open-plan kitchen, breakfast room and informal family living room. The ‘invisible’ kitchen by Fendi comprises floor-to-ceiling chocolate lacquered cabinetry concealing Gaggenau appliances, with marble splashbacks. Beyond the kitchen is a fully equipped separate staff/professional kitchen and wine vault, allowing for large scale entertaining of the highest calibre.

Listed for £10.95m, visit wetherell.co.uk

Chipstead Street, Fulham, SW6

Located in one of Fulham’s most sought-after streets, this outstanding six-bedroom Victorian ‘Lion House’ unfurls across four spacious floors, accompanied by a handsomely landscaped southwest-facing garden. Having been totally refurbished and extended by the current owners, this turnkey home boasts a rare full-basement extension beneath the entire footprint of the plot and garden.

One of the largest and most striking properties on the Peterborough Estate, the lower ground floor is currently set up as a versatile open-plan space with a media room, office, WC and utility area. The attractive ground floor kitchen has pale green Tom Howley shaker cabinetry and is topped by pale stone worktops with integrated Miele appliances. This leads to a gorgeous garden via fully retractable bifold doors, while a skylight floods the space with natural light. Elsewhere, the first floor is devoted to two generous bedrooms.

Listed for £5.5m, visit sothebysrealty.co.uk

Culross Street, Mayfair, W1K

Set in the very heart of Mayfair, just a stone’s throw from Hyde Park, Culross House stands as a rare and unique modern mansion, executed to an impeccable standard. Spread over 8,000 square feet, across six levels, the six-bedroom, six-bathroom home is connected by a glass lift. The stunning landscaped garden at the rear is visible immediately from the entrance hall, while marble floors, polished plaster walls, and custom joinery lend a sense of regal glamour.

A 30ft reception room opens directly onto the terrace, while upstairs, two vast bedroom suites occupy the principal floor, each with a dressing room and marble bathroom, with three further suites arranged above. Below ground, a club room with bar and cinema, a fantastic gym with glass floor, and a swimming pool lined in Kenya black marble, illuminated by fibre optic lighting, delivers on all fronts.


Listed for £20m, visit sothebysrealty.co.uk

Chelsea Park Gardens, Chelsea, SW3

Sprawling across four principal floors, this deceptively spacious low-built house offers an outstanding 4,036 square feet of thoughtfully balanced and intelligently designed accommodation, tailored to contemporary family living. With its wide floorplates, landscaped garden and chic interiors, it is a rare find in one of Chelsea’s most sought-after addresses.

The stunning ground floor is the heart of the home, with a front-facing kitchen and a dining/reception room that opens directly onto a gloriously mature 64ft south-facing garden. The lower ground floor has been cleverly maximised in scale, form and light, with a great reception space that flows into a chic bar and media room. A bedroom with ensuite, utility room and courtyard complete this level, while a spiral staircase leads to the gym and study at the end of the garden.

Listed for £8.95m, visit sothebysrealty.co.uk


Ellerby Street, SW6

A unique and impressive six-bedroom residence, this beautiful home has been diligently finished throughout. Boasting a spacious open-plan kitchen and dining area at its heart, the all-important space is flooded with natural light due to expansive sliding doors that lead out to the flawless 50ft garden. The award-winning kitchen, created by DesignSpace London, features a central island, integrated Gaggenau and Miele appliances, and an extensive array of custom cabinetry designed for both style and functionality.

The lower ground floor and basement levels feature a sizeable media/playroom with direct access to the garden via a private stairwell. Sitting pretty on this desirable street, the home is extremely close to the green expanses of Bishops Park and the picturesque River Thames.

Listed for £4m, visit knightfrank.co.uk

Alexander Street, Notting Hill, W2

A refined and timeless four-bedroom townhouse, this charming home seamlessly blends period charisma and modern living behind its blonde brick and white stucco façade.
Standing five storeys high, the series of well-balanced living spaces benefit from a well thought-through layout, from a ground floor designed for social flow and filled with natural light, to the first floor, where two reception rooms offer versatility and volume.

Ascending to the second floor, the principal bedroom enjoys the privacy of a level to itself, while two further bedrooms crown the top floor. The lower ground floor brings a modern element to the home’s heritage framework, with stone floors flowing through to a media or games room. A versatile additional room lies adjacent, offering flexibility as a guest bedroom, home gym or creative studio, with direct access to the garden.

Listed for £5.35m, visit domusnova.com

Read more: The most beautiful period properties for sale in London